The prior art has shown that nutritional adjunctive therapy given to patients either by mouth (enteral) or by vein (parenteral) is efficacious in reversing catabolism and stimulating anabolism. This improvement in the metabolic state of the patient is believed critical to the healing process and required for patient survival. However, it has been observed the patients receiving chemically defined parenteral and enteral nutritional regimens often have compromised host defense mechanisms. This compromise of the immune system, even while the metabolic system is improving, may lead to increased morbidity and mortality as a result of sepsis and multiple organ failure.
In recent years attention has been focused on identifying the biochemicals or nutrients that are missing from all commercially available parenteral nutritional products and all commercially available defined formula enteral diets. It has been demonstrated by Rudolph and Van Buren that the addition of nucleic acids (RNA) to defined formula diets fed to animals resulted in improved host defense mechanisms. Further, Barul and Daly have shown that when arginine is fed at levels exceeding the body's need for protein synthesis, host defense mechanisms are enhanced. This is evidenced by increased blastogenesis of lymphocytes in response to mitogens in animals and man; reduced tumor appearance and incidence; increased survival in animals; and increased receptivity of cells to lymphokines.
It has also been observed that omega-6 fatty acids (polyunsaturated vegetable oils typically found as the source of lipids in nutritional products) enter the body's metabolic pathways where they serve as precursors to the family of prostaglandins associated with inflammation and suppression of host defense mechanisms. Omega-3 fatty acids (typically found in fish oils) administered to man or animals either parenterally or enterally, enter the biosynthetic pathways and are preferentially converted to the family of prostaglandins that have not been found to be either inflammatory in nature nor immunosuppressive.
Alexander has disclosed that when omega-3 fatty acids and supplemental arginine are fed to burned guinea pigs and humans, improved host defense mechanisms resulted, as determined by a reduction in the incidence of sepsis and overall morbidity.
Each of the biochemicals and nutrients cited above when administered alone provided some level of increased immunoenhancement or decreased immunosuppression in animals and humans given defined formula parenteral or enteral nutrition. However, the prior art is silent as to the administration to animals or man of combinations of these compounds either with or without increased levels of micro-nutrients for immunoenhancement.